The Democrats' refusal to approve $5.7-billion demanded by Trump for the wall project has paralysed Washington, with the president retaliating by refusing to sign off on budgets for swaths of government departments unrelated to the dispute.

As a result, workers as diverse as FBI agents, air traffic controllers and museum staff, did not receive paychecks on Friday.

The partial shutdown of the government became the longest on record at midnight on Friday when it overtook the 21-day stretch in 1995-1996 under president Bill Clinton.